#include <cassert>
#include <iostream>
#include <queue>
#include <random>
#include <set>
#include <utility>
#include <vector>
const size_t SQRT = 300;
std::vector<std::pair<int, int>> merge_sqrt(std::vector<std::pair<int, int>>& a, std::vector<std::pair<int, int>>& b, std::vector<int>& seenby) {
int key = std::random_device()();
assert(a.size() <= SQRT + 1);
assert(b.size() <= SQRT + 1);
std::vector<std::pair<int, int>> res;
res.reserve(SQRT + 1);
int ap, bp; // pointers to current elements to consider
ap = bp = 0;
while (res.size() < SQRT + 1) {
if (ap < a.size() && seenby[a[ap].second] == key) {
++ap;
} else if (bp < b.size() && seenby[b[bp].second] == key) {
++bp;
} else if (ap == a.size()) {
if (bp == b.size()) return res;
seenby[b[bp].second] = key;
res.push_back(b[bp++]);
} else if (bp == b.size()) {
seenby[a[ap].second] = key;
res.push_back(a[ap++]);
} else if (a[ap] > b[bp]) {
seenby[a[ap].second] = key;
res.push_back(a[ap++]);
} else {
seenby[b[bp].second] = key;
res.push_back(b[bp++]);
}
}
return res;
}
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int n, m, q;
std::cin >> n >> m >> q;
std::vector<std::vector<int>> upadj(n), downadj(n);
for (int i = 0; i < m; ++i) {
int u, v;
std::cin >> u >> v;
--u, --v;
upadj[v].push_back(u);
downadj[u].push_back(v);
}
std::vector<std::vector<std::pair<int, int>>> furthest_ancestors(n); // (dist, index)
std::vector<int> mergerseen(n);
auto precalc = [&](int node) -> void {
furthest_ancestors[node] = {{-1, node}};
for (int to : upadj[node]) {
furthest_ancestors[node] = merge_sqrt(furthest_ancestors[node], furthest_ancestors[to], mergerseen);
}
for (auto& [dist, index] : furthest_ancestors[node]) {
++dist;
}
};
for (int i = 0; i < n; ++i) precalc(i);
std::vector<int> is_removed(n);
while (q--) {
int partytown, removed;
std::cin >> partytown >> removed;
--partytown;
std::vector<int> which_removed(removed);
for (int& i : which_removed) std::cin >> i, --i;
for (int i : which_removed) is_removed[i] = true;
if (removed > SQRT) {
// solve in one big dfs
std::vector<int> distance(n, -1);
distance[partytown] = 0;
int max = -1;
for (int i = n - 1; i >= 0; --i) {
int maxx = -1e9;
for (int to : downadj[i]) {
maxx = std::max(maxx, distance[to]);
}
if (i != partytown) {
distance[i] = maxx + 1;
}
if (!is_removed[i]) {
max = std::max(max, distance[i]);
}
}
std::cout << max << '\n';
} else {
// use preprocess
int ans = -1;
for (auto [dist, node] : furthest_ancestors[partytown]) {
if (is_removed[node]) continue;
ans = dist;
break;
}
std::cout << ans << '\n';
}
for (int i : which_removed) is_removed[i] = false;
}
}
